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ASF GitHub Bot commented on DRILL-6373: --------------------------------------- vrozov commented on issue #1244: DRILL-6373: Refactor Result Set Loader for Union, List support URL: https://github.com/apache/drill/pull/1244#issuecomment-406811356 @paul-rogers The change to `NullableVarCharVector` that was part of your PR exposed a bug that is part of the existing code. Please see `AbstractMapVector.java:48`. The problem is that a newly created map vector references a newly created deep copy(clone) of the passed `MaterializedField` while newly created child vectors of the map vector references children of **another** instance of the `MaterializeField`. If that **other** instance is completely immutable it would not cause any problem (except that now there is no reason to create deep copy), but with your changes there was an attempt to mutate from different threads the **other** instance as that **other** instance is used to create multiple outgoing vectors. I hope that this explains what I mean when referring to **existing** bug. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org > Refactor the Result Set Loader to prepare for Union, List support > ----------------------------------------------------------------- > > Key: DRILL-6373 > URL: https://issues.apache.org/jira/browse/DRILL-6373 > Project: Apache Drill > Issue Type: Improvement > Affects Versions: 1.13.0 > Reporter: Paul Rogers > Assignee: Paul Rogers > Priority: Major > Attachments: 6373_Functional_Fail_07_13_1300.txt, > drill-6373-with-6585-fix-functional-failure.txt > > > As the next step in merging the "batch sizing" enhancements, refactor the > {{ResultSetLoader}} and related classes to prepare for Union and List > support. This fix follows the refactoring of the column accessors for the > same purpose. Actual Union and List support is to follow in a separate PR. -- This message was sent by Atlassian JIRA (v7.6.3#76005)